MicroRNA-19 upregulation attenuates cardiac fibrosis via targeting connective tissue growth factor.

BACKGROUND: Previous studies have shown the role of microRNA (miR)-19 in aging-related heart failure. The present study aimed to verify the effects of miR-19 on cardiac fibrosis and its target. METHODS: Cardiac fibrosis was induced by myocardial infarction (MI)-induced heart failure and angiotensin (Ang) II-treated rats in vivo, and was induced in Ang II-treated cardiac fibroblasts (CFs) in vitro. RESULTS: The expression of miR-19 was reduced in the heart tissue of MI and Ang II-treated rats, and Ang II-treated CFs. The impaired cardiac function in rats was repaired after miR-19 administration. The levels of collagen I, collagen III and transforming growth factor-beta (TGF-ß) increased in the heart tissue of MI and Ang II-treated rats, and Ang II-treated CFs. These increases were reversed by miR-19 agomiR. Moreover, the bioinformatic analysis and luciferase reporter assays demonstrated that connective tissue growth factor (CTGF) was a direct target of miR-19. MiR-19 treatment inhibited CTGF expression in CFs, while CTGF overexpression inhibited miR-19 agomiR to attenuate the Ang II-induced increases of collagen I and collagen III in CFs. The increases of p-ERK, p-JNK and p-p38 in the CFs induced by Ang II were repressed by miR-19 agomiR. CONCLUSIONS: Upregulating miR-19 can improve cardiac function and attenuate cardiac fibrosis by inhibiting the CTGF and MAPK pathways.

The anti-tumor effect and biological activities of the extract JMM6 from the stem-barks of the Chinese Juglans mandshurica Maxim on human hepatoma cell line BEL-7402.

Juglans mandshurica Maxim is a traditional herbal medicines in China, and its anti-tumor bioactivities are of research interest. Bioassay-guided fractionation method was employed to isolate anti-tumor compounds from the stem barks of the Juglans mandshurica Maxim. The anti-tumor effect and biological activities of the extracted compound JMM6 were studied in BEL-7402 cells by MTT, Cell cycle analysis, Hoechst 33342 staining, Annexin V-FITC/PI assay and Detection of mitochondrial membrane potential (ΔΨm). After treatment with the JMM6, the growth of BEL-7402 cells was inhibited and cells displayed typical morphological apoptotic characteristics. Further investigations revealed that treatment with JMM6 mainly caused G2/M cell cycle arrest and induced apoptosis in BEL-7402 cells. To evaluate the alteration of mitochondria in JMM6 induced apoptosis. The data showed that JMM6 decreased significantly the ΔΨm, causing the depolarization of the mitochondrial membrane. Our results show that the JMM6 will have a potential advantage of anti-tumor, less harmful to normal cells. This paper not only summarized the JMM6 pick-up technology from Juglans mandshurica Maxim and biological characteristic, but also may provide further evidence to exploit the potential medicine compounds from the stem-barks of the Chinese Juglans mandshurica Maxim.

Study of the upregulation of the activity of cytochrome P450 3A isoforms by Astragalus injection and Astragalus granules in rats and in cells.

Astragalus injection (AI) and Astragalus granules (AG) are the two representative clinical preparations from Astragali Radix. In order to investigate the regulation of metabolism, AI and AG were tested for their ability to affect the major enzyme cytochrome P450 3A isoforms in vivo and in vitro. In the study of CYP3A1 enzyme activity, male rats were pretreated with AI and AG. The "cocktail" approach-based LC-MS/MS results showed that AI pretreatment at 0.16, 0.8 and 4 g kg(-1) day(-1) significantly increased the rat liver microsome CYP3A1 activity by 1.62-, 1.68- and 2.00-fold, and AG pretreatment at 32, 160 and 800 mg kg(-1) day(-1) significantly increased the rat CYP3A1 activity by 1.86-, 2.16- and 1.76-fold. The effects of AI and AG on liver microsome CYP3A1 mRNA expression in rats were analyzed using real-time PCR technique. The results showed that AI and AG pretreatments significantly increased the CYP3A1 mRNA expression. The induction of CYP3A4 enzyme activity by AI and AG in vitro was measured using a CYP3A4 luciferase reporter gene assay in transiently transfected human intestinal LS174T cells. Compared to the control group, AI at 62.5-1,000 mg/ml could significantly induce CYP3A4 reporter gene luciferase activity of 1.36- to 1.88-fold for 48-h incubated PXR-transfected LS174T cells, and AG at 62.5-1,000 µg/ml significantly transactivated CYP3A4 reporter gene luciferase activity of 1.36- to 2.05-fold. However, the CYP3A4 reporter gene construct was not significantly transactivated by the AI and AG in CAR-transfected LS174T cells. These CYP3A isoforms upregulation results can help us to use AI and AG rationally in the clinic.